"On my part, I remain committed to the process of dialogue. It is my firm belief that dialogue and a willingness to look with honesty and clarity at the reality of Tibet can lead us to a viable solution."

The China Film Director’s Guild said Tseden was taken away by the police at Xining airport in China’s Qinghai province on June 25 and was held in police custody.

On the afternoon of June 27, the director was admitted to the hospital, according to the guild.

The guild reported that Tseden (aka Wanmacaidan) was held for “disrupting social order.” Other sources suggest that his offence was to have forgotten a piece of luggage in the departure hall.

“We are very concerned about the reasons why this incident took place and how it will develop. We call for the authorities to respond to the society’s demands swiftly and reveal all the details, including the reasons why the police had to [take away Tseden] forcibly and whether unnecessary violence was involved,” the guild said in a statement.

It is not immediately clear whether Tseden’s arrest is related to his work as a director. He has made films in Tibetan and tells stories about Tibetan culture.

Tseden’s arrest raises questions about whether, under China’s current crackdown on freedom of expression, stories highlighting Tibetan culture are now being interpreted as separatist.

“(President Xi Jinping’s increasing control over ideology) has been carried over into the artistic realm. To what extent will artists have freedom to produce works?” William Nee, China researcher at Amnesty International, told Variety.

“This is certainly not an ordinary criminal case as he was taken away to another place. It is suspicious,” veteran China watcher Johnny Lau Yui-siu said. “But at this point we don’t know the actual cause for the arrest.”

Lau said the fact that Tseden is internationally famous could also have contributed to his troubles. “The more famous you are internationally, the greater the threat you are to China. Look at Liu Xiaobo and Ai Weiwei,” he said.

Tseden’s 2015 comedy “Tharlo” premiered in Venice’s Orrizonte section and won multiple international awards, including the Grand Prize at Tokyo Filmex and best adapted screenplay at the Golden Horse Film Festival in Taiwan.

Tharlo is the name of a Tibetan shepherd character who is search for his identity. “In Tibetan areas, this kind of case is still very common,” Tseden told AFP in 2015.

China’s Sina reported that Tseden lives in Beijing and went to Xining to promote a new film. His arrest was not reported until the news was leaked on social media a few days later. Sina published photos of the director’s hand and wrist covered with bruises and injuries, allegedly caused by the police during the arrests.

Tseden suffers from chronic illness and his health condition during the detention was worrying, the guild said.

Tseden’s friend, filmmaker and sound designer Dorjee Tsering, exposed the details of Tseden’s arrest and conditions on his Weibo account. “The airport police used fetters to detain him,” he wrote, adding that the director suffered from dizziness and felt ill during the detention. But his posting was swiftly removed. Director Jia Zhangke also expressed concern on his Weibo page.